PyTorch NaNs Are Silent Killers — So I Built a 3ms Hook to Catch Them at the Exact Layer

# AI Training's Hidden Time-Waster: When Models Silently Break Down Machine learning models can fail without any warning—producing garbage results while appearing to work normally, wasting hours or days of computing time and effort. A developer created a lightweight detection tool that catches these hidden failures instantly, pinpointing exactly where and when problems occur so they can be fixed immediately instead of discovered later when it's too late to salvage the work.